Mapwel Limits

This chapter is a summary of various limits of mapping with Mapwel software. Some of these limits are imposed by IMG file format (native format of Garmin GPS units), others are result of GPS firmware, Mapwel data structures, license levels, etc.

Map type

Current version of Mapwel does not support marine maps.

Image size

Maximum image size that current version of Mapwel can handle is 30000 x 30000 pixels. However, such image in raw (uncompressed) form requires large memory space (about 2.7 gigabytes). Moreover, Mapwel needs about 3-4 times more memory to do operations with image. If you need to work with large images, please make sure that your computer has enough memory.

Please note: rotation can increase the size of image. Therefore, rotated image can exceed size limit even if original image fits into the limit


Current version of Mapwel supports following projections:

Autovectorization - user styles

Current version of Mapwel supports max. 86 colors for autovectorization. These colors are represented by user defined styles (polygons, in this case). Assign different Map Set Data (main menu > File > Properties > ID tab) to all your maps if they contain user defined styles. This ensures displaying of map with correct colors in the GPS. GPS uses the same color palette for all maps in a map set. Therefore, maps with different palettes are not displayed correctly if they have the same Map Set Data.

IMG file

IMG file can contain single map or it can contain several maps combined into a single file. Current version of Mapwel can produce IMG files of max. 17-30 megabytes size, depending on number of text labels (17 megabytes without text labels). This applies to an IMG file that contains single map (tile). Multiple IMG files can be merged together into a much larger IMG file, which can have hundreds of megabytes or even several gigabytes.

Mapwel can handle 20000 cities in the single map.

Another limiting factor is number of all objects in a single map. The limit is approximately 8 millions of objects. Some objects must be split (automatically) when exported to IMG file, so the number of objects can change during conversion.


Data format of IMG files restricts accuracy of maps by truncating coordinates. This restriction is related to the map scope. It means that very large map is represented in GPS with lower accuracy than the small or normal size map. Mapwel automatically converts all map data into the best possible accuracy level.

Map smaller than 45 has accuracy +-2.4 m, larger map smaller than 90 has accuracy +-4.8 m. Even larger map has accuracy +-9.6 m.

Above mentioned accuracy refers to latitude direction. It also applies to longitude direction on equator. Moving away from equator the accuracy in longitude direction becomes better as parallels become shorter.

OSM file

OpenStreetMap files are often very large. If OSM file is too large for direct opening and processing in Mapwel, please use OSM Splitter tool in Mapwel.


Mapwel is available for download and testing in FREE demo mode. Demo is fully functional except the limit on number of objects (map elements) that can be uploaded into the GPS. Therefore, maps uploaded into GPS with demo are incomplete. Demo does not truncate autovectorized maps. However, it stamps text 'Mapwel Demo' to autovectorized maps. Demo version does not support routing. Routable roads are converted to common roads.

Demo version does not truncate maps if they are located in a 'safe test area' S00.5 - N00.5, W000.5 - E000.5 (WGS84). Place your map within these boundaries to test it in the GPS.

Routing is supported in the safe test area.

Mapwel license levels

Registered Mapwel software is available in two levels:

Basic, for single GPS unit. Basic version allows user to upload map only into the GPS with ID that was used for registration. This version is intended for personal use. Basic version does not allow to export map into other than *.MPW format.

Advanced, for unlimited number of GPS units. However, Advanced version requires one GPS (the one used for registration) to check validity of password after installation or re-installation of Mapwel. Then user may attach any other compatible GPS and upload maps into it. User should have registered GPS by hand when upgrading (re-installing) Mapwel. This version is intended for personnel or organizations that own number of GPS units. Advanced version allows to export maps into IMG, KML and MP format and supports batch conversion mode.

Hardware and software requirements

Windows 98/Me, Windows NT/2000/XP, Windows Vista, Windows 7, Windows 8, Windows 10.